Java Cassandra 异常 timeuuid

Question

在 java 中，插入 cassandra 时出现此错误，我还尝试了时间戳数据类型，

那么是发布日期类型，还是java代码？您能否建议更改代码

读取 csv 文件。

错误:

Exception in thread "main" com.datastax.driver.core.exceptions.InvalidQueryException: Invalid STRING constant (2012/11/11) for "fl_date" of type timeuuid

结构:fl_date时间uuid，

代码:

    System.out.println("Processing CSV file ...");
    List<Flight> flightList = ProcessFlightsCSV.processFlights("flights_from_pg.csv");

    for (Flight flight : flightList) {

        System.out.println(flight);

        Insert query = QueryBuilder.insertInto("flights")
                .value("id", flight.getId())
                .value("year", flight.getYear())
                .value("fl_date", flight.getFlDate())
                .value("airline_id", flight.getAirlineId())
                .value("carrier", flight.getCarrier())
                .value("fl_num", flight.getFlNum())
                .value("origin_airport_id", flight.getOriginAirportId())
                .value("origin", flight.getOrigin())
                .value("origin_city_name", flight.getOriginCityName())
                .value("origin_state_abr", flight.getOriginStateAbr())
                .value("dest", flight.getDest())
                .value("day_of_month", flight.getDayOfMonth())
                .value("dest_city_name", flight.getDestCityName())
                .value("dest_state_abr", flight.getDestStateAbr())
                .value("dep_time", flight.getDepTime())
                .value("arr_time", flight.getArrTime())
                .value("distance", flight.getDistance())
                ;

        session.execute(query.toString());
    }
}
}

Answer 1

Cassandra 中没有直接方法可以将字符串日期时间转换为 TimeUUID。因此，您需要根据日期时间值创建 timeuuid。这是一个简单的例子:

    long fl_date_in_mili = // some code to get millisecond time from flight.getFlDate(); DO it yourself, As we don't know what kind of datatype it is.
    ...
    ...
    UUID fl_date_time_uuid = UUIDs.endOf(fl_date_in_mili);
    // or
    UUID fl_date_time_uuid = UUIDs.startOf(fl_date_in_mili);

    ...
    ...
    ...
    Insert query = QueryBuilder.insertInto("flights")
            .value("id", flight.getId())
            ......
            .value("fl_date", flDateTimeUUID)
            .value("airline_id", flight.getAirlineId())
            .....

这里我们使用:com.datastax.driver.core.utils.UUIDs；可以在 datastax cassandra 驱动程序中找到。